How to Compare the two database tables(table1,Table2) and update the difference into (table2) using c#

bruze

Can any one Help I am trying Compare the two database tables(table1,Table2) and update the difference into (table2) using c#. I have Compared two tables and got the difference value. How to update the difference value into table2 particular row? Student.aspx ************* In aspx page I have added the three Gridview

Student.aspx.cs
********************
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class Student : System.Web.UI.Page
{
Comapre objComapre = new Comapre();
protected void Page_Load(object sender, EventArgs e)
{
DataTable First=new DataTable();
DataTable Second = new DataTable();
DataTable Compare = new DataTable();

  First = objComapre.GetStudentTableOne();
  Second = objComapre.GetStudentTableTwo();
  Compare=compareDataTables(First, Second);

  GridView1.DataSource = First;
  GridView1.DataBind();
  GridView2.DataSource = Second;
  GridView2.DataBind();
  GridView3.DataSource = Compare;
  GridView3.DataBind();
}

public DataTable compareDataTables(DataTable First, DataTable Second)
{
    First.TableName = "FirstTable";
    Second.TableName = "SecondTable";

    //Create Empty Table
    DataTable table = new DataTable("Difference");

    try
    {
        //Must use a Dataset to make use of a DataRelation object
        using (DataSet ds = new DataSet())
        {
            //Add tables
            ds.Tables.AddRange(new DataTable\[\] { First.Copy(), Second.Copy() });

            //Get Columns for DataRelation
            DataColumn\[\] firstcolumns = new DataColumn\[ds.Tables\[0\].Columns.Count\];

            for (int i = 0; i < firstcolumns.Length; i++)
            {
                firstcolumns\[i\] = ds.Tables\[0\].Columns\[i\];
            }

            DataColumn\[\] secondcolumns = new DataColumn\[ds.Tables\[1\].Columns.Count\];

            for (int i = 0; i < secondcolumns.Length; i++)
            {
                secondcolumns\[i\] = ds.Tables\[1\].Columns\[i\];
            }

            //Create DataRelation
            DataRelation r = new DataRelation(string.Empty, first